They were four bills passed by the Federalist in the 5th United States Congress and signed into law by president John Adams int the aftermath of the French Revolution and during an undeclared naval war with France. Authored by the Federalists the laws were designed under the guise national security but most historians include it was really intended to decrease the number of voters who disagreed with the Federalist party. At the time, most immigrants supported Thomas Jefferson and the Democratic-Republicans, the political of the Federalists. This act was repealed in 1802 by the Naturalization Law of 1802.
